All these speeds the providers advertise (especially the faster ones) are often cut down by bad peering. I often had an issue downloading bigger files from my storage when I was traveling. Only got some single digit MBit transfer speeds due to bad peering, while speed tests has shown decent results. When it comes down to Selfhosting the upload/download figures alone not always tell the truth. In my point of view 20Mbps is actually even sufficient for most of private stuff, even streaming HD content to one ore two peers simultaneously.